WASHINGTON (AP) — House Speaker Nancy Pelosi said Sunday that senators will “pay a price” if they block new witnesses in Donald Trump’s impeachment trial, but the president quickly retorted that she and House Intelligence Chairman Adam Schiff should also testify.

The House plans to vote this week to transmit the articles of impeachment to the Senate for the historic trial on charges of abuse of power and obstruction of Congress over Trump’s actions toward Ukraine. It will be only the third impeachment trial in American history.

Trump tweeted right before and after Pelosi’s appearance, in both instances using derisive nicknames. He said both she and Schiff should appear in the Senate for testimony.